Each year, millions of elderly people around the world (especially women) experience falls resulting in hip fractures (mainly, femoral neck fractures).
Hip fractures in the elderly result in physical suffering, loss of independence, a deteriorating mental state and high mortality rate.
Conventional hip protector devices are of a passive type. Typically, they comprise a hard high-density plastic shield and soft foam pads. These devices are usually inserted into especially designed pockets located over the hips, in undergarments, pants or belts.
Conventional passive hip protector devices have fundamental shortcomings especially:                There is no unambiguous evidence as to their efficacy in preventing hip fractures        Their cumbersome design and wearing result in low client compliance        
The following brief citations were taken from articles published in three professional magazines. The articles report on three independent clinical trials of conventional passive hip protectors carried out in The US and the UK.
Their conclusions demonstrate the above mentioned shortcomings:
According to an article published in the professional magazine: JAMA (the Journal of the American Medical Association), Douglas P. Kiel, M D, MPH et al., 2007; 298: 413-422, titled:
Efficacy of a Hip Protector to Prevent Hip Fracture in Nursing Home Residents:
Coclusions: In this clinical trial of an energy-absorbing/shunting hip protector conducted in US nursing homes, we were unable to detect a protective effect on the risk of hip fracture, despite good adherence to protocol. These results add to the increasing body of evidence that hip protectors, as currently designed are not effective for preventing hip fracture among nursing home residents.
According to an article published in the professional magazine: PubMed.gov, Parker M J et al., (July 2005), titled:
Hip protectors for preventing hip fractures in older people:
                Authors' conclusions: Accumulating evidence casts some doubt on the effectiveness of the provision of hip protectors in reducing the incidence of hap fractures in older people. Acceptance and adherence by users of the protectors remain poor due to discomfort and practicality.        
According to an article published in the professional magazine:
Age and Ageing, Yvonne F. Birks, et al., 2003, vol. 32 no. 4. British Geriatric Society titled:
Randomized controlled trial of hip protectors for the prevention of second hip fractures:
Key Points                The current evidence to support the use of hip protectors comes from residential care settings.        This report describes the results of a secondary prevention trial in a community-based sample.        No evidence for their efficacy in this sample.        More work is required to test them in larger trials in both residential and community settings.        
Several attempts to develop an active hip protector device were made, but none of them materialized into a viable solution.
This may be explained by two main reasons:                Technical obstacle: A failure to implement a reliable fall detection method and logic that will avoid false alarms and faulty system activations.        Compliance issue: A failure to design a comfortable wearable product that will be adopted by the elderly        
An example of such an attempt could be an active inflatable hip protector device described in U.S. Pat. No. 5,500,952 of Keyes, which is incorporated by reference for all purposes as if fully set forth herein.
The hip inflatable protection device contains motion sensors, an inflatable air bag folded into pleats, a battery, a gas cartridge, sensors to determine angular motion and acceleration, a triggering mechanism to release the gas and a relief valve.
When the user falls, the sensors automatically release gas from the cartridge and inflate the airbag assembly.
The motion sensors, according to Keyes, contain logic controlled circuits which do not permit inflation of the airbag assembly unless signals are received indicating both sufficient acceleration of the body and sufficient downward angular motion.
The sensors according to Keyes may include acceleration and orientation sensors.
When the hip inflatable protection device senses body movement of a selected and predetermined acceleration and senses downward angular motion of selected and predetermined magnitude, the device signals the triggering mechanism to fire. This releases compressed gas from the compressed gas cartridge inflating the invention.
After use the relief valve is opened to release air from the airbag assembly, the pleats are reinserted into the hip inflatable protection device, a gas cartridge is replaced and the hip inflatable protection device is ready for reuse.
The fact that, as of now, there is no effective solution to active real-time hip fracture prevention caused by falls is unambiguous.
Previous attempts to provide real-time active hip fracture prevention solutions lacked the capability to provide continuous measurement of the distance or height of the pelvis and the hips relative to the ground. Likewise, they lacked the combination of hip proximity to the ground data with pelvis vertical velocity and acceleration data in order to reliably detect falls.
Basing the assessment of a falling situation on angular diversion of the body could result in false activation, since as a person can regain balance after losing it, for example by means of grabbing a nearby piece of furniture. Namely, the solutions known today are not capable of properly and distinctly recognizing a situation of impending inevitable collision with the ground.
The invention described hereinafter is intended to solve the above mentioned deficiencies and suggest an innovative technical and device design approach.
By adding a robust height measurement system that will be placed on the body and cross referencing the height data with other sensors, the system will allow, for the first time, for significantly lower and acceptable false negative and false positive detection rates that will in turn enable the system to be put to real world usage.